1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for transmitting a synchronization signal in a carrier aggregation system.
2. Related Art
A carrier aggregation system has recently drawn attention. The carrier aggregation system implies a system that configures a broadband by aggregating one or more component carriers (CCs) having a bandwidth smaller than that of a target broadband when the wireless communication system intends to support the broadband. In the carrier aggregation system, a term ‘serving cell’ is also used instead of the CC. Herein, the serving cell consists of a downlink component carrier (DL CC) and an uplink component carrier (UL CC), or consists of only the DL CC. That is, the carrier aggregation system is a system in which a plurality of serving cells are assigned to one user equipment.
Conventionally, the carrier aggregation system transmits a synchronization signal in all serving cells by considering backward compatibility, and has the same structure in a frame in which the synchronization signal is transmitted. Herein, the synchronization signal implies a signal used for frame synchronization, cell identifier (ID) acquisition, etc.
However, a further carrier aggregation system can use a new carrier type without consideration of backward compatibility. That is, a transmission method different from the conventional synchronization signal transmission can be used in the new carrier type.